A Russian security service whistleblower who sought refuge in Britain was put on trial in absentia at a tribunal near Moscow yesterday.

Alexander Litvinenko has embarrased the main successor organisation to the KGB by alleging skulduggery, murder plots, corruption, and the bombing of Russian citizens by the security service.

His is the first such case in Russia for 17 years, a fact which may reflect the increased clout of the security agencies under President Vladimir Putin, a former KGB officer and security service chief.

Mr Litvinenko received political asylum in Britain last year when he fled Russia after being acquitted of charges of abuse of office, and having spent nine months in a Moscow jail.

The last such case also involved a defector spy who fled to Britain - the KGB operative Oleg Gordievsky, who was sentenced to death in absentia in 1985 for treason.

Next week, the Russians are to open another trial in absentia, of the US-based former KGB agent Oleg Kalugin. Mr Kalugin faces charges of high treason after testifying in the case of George Trofimoff, a US army colonel who received a life term in the US for spying for Russia and the former Soviet Union.

Like Mr Litvinenko and his patron, Boris Berezovsky, the billionaire businessman who has also fled to London to avoid prosecution in Russia after falling foul of Mr Putin, Mr Kalugin is a severe critic of the Russian president.

The Litvinenko trial is being conducted in camera by a military tribunal sitting 40 miles south of Moscow. The prosecution teams are in a race against the clock in both the Litvinenko and Kalugin trials, because trials in absentia are to be outlawed from July under new regulations.

Mr Litvinenko alleges that his ex-employer, the FSB, or federal security service, was responsible for the bombings of blocks of flats in Moscow and elsewhere in the summer of 1999 that left 300 people dead.

The blasts were blamed on Chechen "terrorists" and Mr Putin used the atrocities to launch his war in Chechnya. Mr Putin had just become Russian prime minister after heading the FSB. As security chief, he met Mr Litvinenko, who claims that his allegations were ignored.

Mr Litvinenko also alleges that while serving in the FSB, he received orders to assassinate Mr Berezovsky. He detailed his allegations in a recent book, which has upset his former employers.

He faces charges of abuse of office and of theft of explosives. In a video linkup with Moscow journalists from London on Monday, he maintained that he was actually being tried because of his book.